Vietnam on Tuesday locked down its third-largest city for two weeks after 15 cases of COVID-19 were found in a hospital, the government said.

Public transport into and out of the central city of Da Nang was cancelled. Over the weekend, thousands of mostly Vietnamese tourists had to end their summer holidays in the popular beach destination.

Authorities estimated several thousand people would be stranded by the transportation shutdown and asked hotels to shelter them.

Women wearing face masks stand on a beach in Vung Tau city, Vietnam, Sunday, July 26, 2020. Vietnam on Sunday reimposed restrictions in one of its most popular beach destinations after a second person tested positive for the virus, the first locally transmitted cases in the country in over three months. (AP PhotoHau Dinh)

Women wearing face masks stand on a beach in Vung Tau city, Vietnam, Sunday, July 26, 2020. Vietnam on Sunday reimposed restrictions in one of its most popular beach destinations after a second person tested positive for the virus, the first locally transmitted cases in the country in over three months. (AP PhotoHau Dinh)

On Sunday, the government ordered unnecessary business to close down and required people to practice social distancing in the city of 1.1 million population.

The outbreak was detected in patients and health workers at Da Nang hospital.

With the new infections, Vietnam has reported 431 cases of COVID-19 without a death.